1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly, to an apparatus and method for driving a liquid crystal display device, which can reduce the number of data driving integrated circuits and compensate for the amount of data charge in a liquid crystal panel to improve picture quality and to reduce power consumption.
2. Discussion of the Related Art
A liquid crystal display device displays images using electro-optical characteristics of a liquid crystal. The liquid crystal shows anisotropic properties having different refractive indexes and different dielectric constants according to long-axis and short-axis directions of molecules and molecule arrangement and optical properties thereof can be easily controlled. The liquid crystal display device using the liquid crystal adjusts the transmittance of light passing through a polarizer by varying the orientation of liquid crystal molecules according to the strength of an electric field, thereby displaying images.
The liquid crystal display device includes a liquid crystal panel including a plurality of pixels arranged in a matrix, a gate driver driving gate lines of the liquid crystal panel, and a data driver driving data lines of the liquid crystal panel.
Each pixel of the liquid crystal panel expresses a desired color by a combination of red, green, and blue sub-pixels that control light transmittance according to a data signal. Each sub-pixel includes a thin film transistor (“TFT”) connected to a gate line and to a data line, and a liquid crystal capacitor connected to the TFT. The liquid crystal capacitor charges a difference voltage between a data signal supplied to a pixel electrode through the TFT and a common voltage supplied to a common electrode and drives liquid crystal according to the charged voltage, thereby controlling light transmittance.
The gate driver includes a plurality of gate integrated circuits (“ICs”) which sequentially drive the gate lines of the liquid crystal panel.
The data driver includes a plurality of data ICs which convert a digital data signal into an analog data signal whenever the gate lines are driven and supply the analog data signal to the data lines of the liquid crystal panel.
The data ICs include a complicated circuit construction, such as a digital-to-analog converter, that increases manufacturing costs. Further, since the number of data lines of the liquid crystal panel is larger than the number of gate lines thereof, more data ICs than gate ICs are required. To reduce the manufacturing costs of the liquid crystal display device, a method for reducing the number of data ICs while maintaining a resolution of the liquid crystal panel has been considered.
For example, a liquid crystal panel which halves the number of data lines using a structure in which odd and even sub-pixels located at both sides of one data line are sequentially driven using the data line has been proposed to reduce the number of the data ICs.
However, although the number of the data ICs is halved by locating the odd and even sub-pixels at both sides of one data line, the amount of data charge is also halved due to time division driving. Therefore, picture defects, such as spots on horizontal lines or vertical lines, are generated. Recently, as display devices become ever larger, a liquid crystal display device, which can prevent defects of picture quality while reducing the number of data ICs below that in a conventional structure in which the number of the data ICs is halved, has been strongly demanded.